NOSTOCYCLAMIDE - A NEW MACROCYCLIC, THIAZOLE-CONTAINING ALLELOCHEMICAL FROM NOSTOC-SP-31 (CYANOBACTERIA)

A new anticyanobacterial and antialgal secondary metabolite, nostocyclamide, that is also toxic against Brachionus calyciflorus has been isolated as a major component from the dinitrogen-fixing cyanobacterium Nostoc 31. Extensive H-1 and C-13 NMR and X-ray analyses proved this compound to be a cyclic peptide which has not previously been observed in other microorganisms. The planar macrocyclic structure exhibits substituted oxazole and thiazole residues that are linked by three peptide units.